fix: view dispose crash on android if view is on background (#453)

* fix: view dispose crash on android if view is on background

* chore: format kotlin code

Author: jokerttu

android/src/main/kotlin/com/google/maps/flutter/navigation/GoogleMapView.kt

@@ -40,8 +40,8 @@ internal constructor(
     // Call all of these three lifecycle functions in sequence to fully
     // initialize the map view.
     _mapView.onCreate(context.applicationInfo.metaData)
-    _mapView.onStart()
-    _mapView.onResume()
+    onStart()
+    onResume()
 
     viewRegistry.registerMapView(viewId, this)
 
@@ -55,28 +55,49 @@ internal constructor(
   }
 
   override fun dispose() {
+    if (super.isDestroyed()) {
+      return
+    }
+
+    viewRegistry.unregisterNavigationView(getViewId())
+
     // When view is disposed, all of these lifecycle functions must be
     // called to properly dispose navigation view and prevent leaks.
-    _mapView.onPause()
-    _mapView.onStop()
+    onPause()
+    onStop()
+    super.onDispose()
     _mapView.onDestroy()
-
-    viewRegistry.unregisterMapView(getViewId())
   }
 
-  override fun onStart() {
-    _mapView.onStart()
+  override fun onStart(): Boolean {
+    if (super.onStart()) {
+      _mapView.onStart()
+      return true
+    }
+    return false
   }
 
-  override fun onResume() {
-    _mapView.onResume()
+  override fun onResume(): Boolean {
+    if (super.onResume()) {
+      _mapView.onResume()
+      return true
+    }
+    return false
   }
 
-  override fun onStop() {
-    _mapView.onStop()
+  override fun onStop(): Boolean {
+    if (super.onStop()) {
+      _mapView.onStop()
+      return true
+    }
+    return false
   }
 
-  override fun onPause() {
-    _mapView.onPause()
+  override fun onPause(): Boolean {
+    if (super.onPause()) {
+      _mapView.onPause()
+      return true
+    }
+    return false
   }
 }

android/src/main/kotlin/com/google/maps/flutter/navigation/GoogleMapsAutoMapView.kt

@@ -41,14 +41,19 @@ internal constructor(
   }
 
   // Handled by AndroidAutoBaseScreen.
-  override fun onStart() {}
+  override fun onStart(): Boolean {
+    return super.onStart()
+  }
 
-  // Handled by AndroidAutoBaseScreen.
-  override fun onResume() {}
+  override fun onResume(): Boolean {
+    return super.onResume()
+  }
 
-  // Handled by AndroidAutoBaseScreen.
-  override fun onStop() {}
+  override fun onStop(): Boolean {
+    return super.onStop()
+  }
 
-  // Handled by AndroidAutoBaseScreen.
-  override fun onPause() {}
+  override fun onPause(): Boolean {
+    return super.onPause()
+  }
 }

android/src/main/kotlin/com/google/maps/flutter/navigation/GoogleMapsBaseMapView.kt

@@ -61,18 +61,69 @@ abstract class GoogleMapsBaseMapView(
   private var _mapReadyCallback: ((Result<Unit>) -> Unit)? = null
   private var _pendingCameraEventsListenerSetup = false
 
-  /// Default values for UI features.
+  // Default values for UI features.
   private var _consumeMyLocationButtonClickEventsEnabled: Boolean = false
 
+  // View lifecycle states.
+  private enum class LifecycleState {
+    NONE,
+    STARTED,
+    RESUMED,
+    PAUSED,
+    STOPPED,
+    DESTROYED,
+  }
+
+  // Current lifecycle state tracks the state of the view.
+  // This is used to avoid calling lifecycle methods in the wrong order.
+  private var currentLifecycleState: LifecycleState = LifecycleState.NONE
+
   abstract fun getView(): View
 
-  abstract fun onStart()
+  open fun onStart(): Boolean {
+    if (
+      currentLifecycleState == LifecycleState.STOPPED ||
+        currentLifecycleState == LifecycleState.NONE
+    ) {
+      currentLifecycleState = LifecycleState.STARTED
+      return true
+    }
+    return false
+  }
 
-  abstract fun onResume()
+  open fun onResume(): Boolean {
+    if (
+      currentLifecycleState == LifecycleState.STARTED ||
+        currentLifecycleState == LifecycleState.PAUSED
+    ) {
+      currentLifecycleState = LifecycleState.RESUMED
+      return true
+    }
+    return false
+  }
 
-  abstract fun onStop()
+  open fun onStop(): Boolean {
+    if (
+      currentLifecycleState == LifecycleState.PAUSED ||
+        currentLifecycleState == LifecycleState.STARTED
+    ) {
+      currentLifecycleState = LifecycleState.STOPPED
+      return true
+    }
+    return false
+  }
 
-  abstract fun onPause()
+  open fun onPause(): Boolean {
+    if (currentLifecycleState == LifecycleState.RESUMED) {
+      currentLifecycleState = LifecycleState.PAUSED
+      return true
+    }
+    return false
+  }
+
+  protected fun isDestroyed(): Boolean {
+    return currentLifecycleState == LifecycleState.DESTROYED
+  }
 
   // Method to set the _map object
   protected fun setMap(map: GoogleMap) {
@@ -218,6 +269,33 @@ abstract class GoogleMapsBaseMapView(
     }
   }
 
+  protected open fun onDispose() {
+    getMap().run {
+      setOnMapClickListener(null)
+      setOnMapLongClickListener(null)
+      setOnMarkerClickListener(null)
+      setOnMarkerDragListener(null)
+      setOnInfoWindowClickListener(null)
+      setOnInfoWindowClickListener(null)
+      setOnInfoWindowLongClickListener(null)
+      setOnPolygonClickListener(null)
+      setOnPolylineClickListener(null)
+      setOnMyLocationClickListener(null)
+      setOnMyLocationButtonClickListener(null)
+      setOnFollowMyLocationCallback(null)
+      setOnCameraMoveStartedListener(null)
+      setOnCameraMoveListener(null)
+      setOnCameraIdleListener(null)
+    }
+
+    // Clear surfaceTextureListener
+    val textureView = findTextureView(getView()) ?: return
+    textureView.surfaceTextureListener = null
+    _map = null
+
+    currentLifecycleState = LifecycleState.DESTROYED
+  }
+
   // Installs a custom invalidator for the map view.
   private fun installInvalidator() {
     val textureView = findTextureView(getView()) ?: return

android/src/main/kotlin/com/google/maps/flutter/navigation/GoogleMapsNavigationView.kt

@@ -21,6 +21,7 @@ import android.content.res.Configuration
 import android.view.View
 import com.google.android.gms.maps.CameraUpdateFactory
 import com.google.android.libraries.navigation.NavigationView
+import com.google.android.libraries.navigation.OnNavigationUiChangedListener
 import io.flutter.plugin.platform.PlatformView
 
 class GoogleMapsNavigationView
@@ -46,6 +47,10 @@ internal constructor(
   private var _isReportIncidentButtonEnabled: Boolean = true
   private var _isTrafficPromptsEnabled: Boolean = true
 
+  private var _onRecenterButtonClickedListener: NavigationView.OnRecenterButtonClickedListener? =
+    null
+  private var _onNavigationUIEnabledChanged: OnNavigationUiChangedListener? = null
+
   override fun getView(): View {
     return _navigationView
   }
@@ -54,8 +59,8 @@ internal constructor(
     // Call all of these three lifecycle functions in sequence to fully
     // initialize the navigation view.
     _navigationView.onCreate(context.applicationInfo.metaData)
-    _navigationView.onStart()
-    _navigationView.onResume()
+    onStart()
+    onResume()
 
     // Initialize navigation view with given navigation view options
     var navigationViewEnabled = false
@@ -91,42 +96,60 @@ internal constructor(
   }
 
   override fun dispose() {
-    getMap().setOnMapClickListener(null)
-    getMap().setOnMapLongClickListener(null)
-    getMap().setOnMarkerClickListener(null)
-    getMap().setOnMarkerDragListener(null)
-    getMap().setOnInfoWindowClickListener(null)
-    getMap().setOnInfoWindowClickListener(null)
-    getMap().setOnInfoWindowLongClickListener(null)
-    getMap().setOnPolygonClickListener(null)
-    getMap().setOnPolylineClickListener(null)
+    if (super.isDestroyed()) {
+      return
+    }
+
+    viewRegistry.unregisterNavigationView(getViewId())
+
+    // Remove navigation view specific listeners
+    if (_onRecenterButtonClickedListener != null) {
+      _navigationView.removeOnRecenterButtonClickedListener(_onRecenterButtonClickedListener)
+      _onRecenterButtonClickedListener = null
+    }
+    if (_onNavigationUIEnabledChanged != null) {
+      _navigationView.removeOnNavigationUiChangedListener(_onNavigationUIEnabledChanged)
+      _onNavigationUIEnabledChanged = null
+    }
 
     // When view is disposed, all of these lifecycle functions must be
     // called to properly dispose navigation view and prevent leaks.
-    _navigationView.isNavigationUiEnabled = false
-    _navigationView.onPause()
-    _navigationView.onStop()
+    onPause()
+    onStop()
+    super.onDispose()
     _navigationView.onDestroy()
-
-    _navigationView.removeOnRecenterButtonClickedListener {}
-
-    viewRegistry.unregisterNavigationView(getViewId())
   }
 
-  override fun onStart() {
-    _navigationView.onStart()
+  override fun onStart(): Boolean {
+    if (super.onStart()) {
+      _navigationView.onStart()
+      return true
+    }
+    return false
   }
 
-  override fun onResume() {
-    _navigationView.onResume()
+  override fun onResume(): Boolean {
+    if (super.onResume()) {
+      _navigationView.onResume()
+      return true
+    }
+    return false
   }
 
-  override fun onStop() {
-    _navigationView.onStop()
+  override fun onStop(): Boolean {
+    if (super.onStop()) {
+      _navigationView.onStop()
+      return true
+    }
+    return false
   }
 
-  override fun onPause() {
-    _navigationView.onPause()
+  override fun onPause(): Boolean {
+    if (super.onPause()) {
+      _navigationView.onPause()
+      return true
+    }
+    return false
   }
 
   fun onConfigurationChanged(configuration: Configuration) {
@@ -138,12 +161,17 @@ internal constructor(
   }
 
   override fun initListeners() {
-    _navigationView.addOnRecenterButtonClickedListener {
-      viewEventApi?.onRecenterButtonClicked(getViewId().toLong()) {}
-    }
-    _navigationView.addOnNavigationUiChangedListener {
+    _onRecenterButtonClickedListener =
+      NavigationView.OnRecenterButtonClickedListener {
+        viewEventApi?.onRecenterButtonClicked(getViewId().toLong()) {}
+      }
+    _navigationView.addOnRecenterButtonClickedListener(_onRecenterButtonClickedListener)
+
+    _onNavigationUIEnabledChanged = OnNavigationUiChangedListener {
       viewEventApi?.onNavigationUIEnabledChanged(getViewId().toLong(), it) {}
     }
+    _navigationView.addOnNavigationUiChangedListener(_onNavigationUIEnabledChanged)
+
     super.initListeners()
   }